This application is related to and claims priority, under 35 U.S.C. xc2xa7119, from French Patent Application No. 99 13612, filed on Oct. 29, 1999, the entire contents of which is hereby incorporated by reference herein.
1. Field of the Invention
The present invention relates to a device to amplify the movement of an operating button for a switch, which is used especially when the operating button of the switch has a small range of travel, for example, about one millimeter.
2. Discussion of Background
Switches, of the type discussed above, are used when fast selection switching is required, for example, to prevent rebounding between the contacts of the switch.
In a movement-amplifying device, the operating button is not operated directly, but by means of a pusher that is movable in translation and has a range of travel, for example, about 5 millimeters, which is far greater than the range of travel of the operating button, i.e., about 1 millimeter. The amplified range of travel of the pusher is especially useful for broadening the manufacturing tolerance values for mechanisms, such as a cam, for example, which operate the pusher.
The prior art movement-amplifying devices are complicated. They comprise a large number of mechanical parts, and especially several springs.
The present invention is aimed at simplifying the complicated movement-amplifying devices of the prior art.
To achieve this aim, an object of the present invention is to provide a device to amplify the movement of an operating button of a switch, wherein the switch is fixed in a body of the device. The device includes a pusher which is translatable along a central longitudinal axis of the body and the central longitudinal axis of the body is coincident with a central longitudinal axis of the pusher. The translation of the pusher constitutes the amplified motion. The device includes a varying-diameter cylindrical member having first, second, and third support regions. The first support region of the cylindrical member is capable of moving along a ramp of the pusher when the pusher moves along the central longitudinal axis of the body. The second support region of the cylindrical member is in permanent contact with a region of the body whatever the position of the pusher. The third support region of the cylindrical member is in contact with the operating button of the switch.
An advantage of the present invention is that the movement-amplifying device provides for the depressed and released positions of the pusher to be reversed from the depressed and released positions of the operating button of the switch. In other words, when the pusher is at rest or in a released position, the operating button of the switch is in a depressed position and when the pusher is in a depressed position, the operating button of the switch is in a released position. The reversed states of the depressed and released positions for the pusher and the operating button of the switch are advantageous, particularly for small-motion switches which cannot withstand the sudden action of having their operating button pressed upon because such sudden pressing action could cause damage to the switch. Because of the reversed states of the depressed and released positions of the pusher and the operating button of the switch, the speed with which the operating button is pressed is related to the structure for providing permanent contact between the second support region of the cylindrical structure and the region of the body, for example, by using a spring that maintains this contact. The calibration of this spring controls the speed at which the operating button is pressed and prevents sudden depressing of the operating button so that the switch will not be damaged.
Another advantage of the present invention is that the movement-amplifying device enables the progress of the travel of the operating button to be set as a function of the progress of travel of the pusher. This setting of the progress of the travel of the operating button of the switch as a function of the progress of travel of the pusher is obtained by adapting the shape of the ramp.